The Hymns to Apollo

I was aware that the Homeric Hymn to Apollo is actually a combination of two separate hymns to Delian and Pythian Apollo, but I just discovered an interesting explanation of their joining. In an article on Homer, 1999, West relates that Burkert in 1979 and Janko in 1982 independently observed that Polycrates of Samos celebrated in 523 a festival on Delos that was called both Pythian and Delian. Since the usual dating of the hymns would place the Pythian in the early part of the sixth century, and the Delian in the latter part, this festival, it is suggested, would have been a suitable time for the joining of the more recent Delian hymn to the older Pythian.